A semi-transmitting and semi-reflecting liquid crystal device is a liquid crystal display device provided with both reflector electrode and transparent electrode. This device therefore has a function as a transmitting type liquid crystal display device and a function as a reflecting type liquid crystal device at the same time. Conventionally, earnest researches and developments of this semi-transmitting and semi-reflecting liquid crystal display device have been made from, for example, the following reasons.
(1) The liquid crystal display device is a semi-transmitting and semi-reflecting type. Therefore, it may be used as a reflecting type allowing a liquid crystal display device to be effected by utilizing extraneous light in the open where extraneous light is relatively strong whereas it may be used as a transmitting type allowing a liquid crystal display to be effected by utilizing back light in the interior of a house where extraneous light is relatively weak. Therefore, this display device can display with high brightness whether the display is used in the open or in the interior of a house.
(2) When the liquid crystal display is used in a bright place (under strong extraneous light), it can be used as reflecting type and power consumption can be therefore saved.
(3) The liquid crystal display can be used as a reflecting type in the open and therefore, it can be operated with small power consumption. It is therefore suitable for portable type displays.
(4) A full-color type semi-transmitting and semi-reflecting display device can be easily developed.
However, in the semi-transmitting and semi-reflecting liquid crystal display, a reflector electrode and a transparent electrode must be disposed in the same pixel in a liquid crystal driving electrode portion, giving rise to the problem that the production process is complicated, and a reduction in yield and cost-up are caused and the problem that an image seen on a transmitting type liquid crystal display is different from that on a reflecting type and there is therefore a difficulty in seeing an image.
In light of this, the following Patent References 1 and 2 disclose semi-transmitting and semi-reflecting liquid crystal driving electrodes respectively having a structure in which a silver reflecting film is formed, then this silver reflecting film is covered with a protective film and a liquid crystal driving transparent electrode is formed on the protective film. These silver reflecting layer and liquid crystal driving transparent electrode are alternately arranged to thereby form a semi-transmitting and semi-reflecting liquid crystal driving electrode having a semi-transmitting and semi-reflecting function.
Also, the following Patent Reference 3 discloses a semi-transmitting reflecting film produced by further forming a Si thin film having an auxiliary reflecting function beneath a metal-based semi-transmitting reflecting layer.
Patent Reference 1: Publication of Japanese Patent Application Laid-Open (JP-A) No. 2002-49034
Patent Reference 2: Publication of JP-A No. 2002-49033
Patent Reference 3: Publication of JP-A No. 2001-305529